msem-instigator

Enchant creature
Enchanted creature gets +2/+2.
When Seeking Horizons is put into your graveyard from anywhere other than your library, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Mill five cards, then you may exile any number of cards from your graveyard. Create an X/X black Horror creature token with menace, where X is the number of cards exiled in this way. (To mill five cards, put five cards from the top of your library into your graveyard.)

Flying
Whenever Seer of Clear Skies or another creature you control with flying attacks, that creature gets +1/+1 until end of turn.

Creatures with power less than Seer of the Hunt's power can't block it.

Whenever you scry, draw a card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{W}: Create a 1/1 white Human Samurai creature token.

When Seikatsu Warleader enters, if it's not a token, create a token that's a copy of target creature token you control.

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Spirit creature token.

When Seishin Rageshaper enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have haste.

When Seishin Smokeshaper enters, create a 2/2 colorless Spirit creature token.
Whenever you cast a noncreature spell, colorless creatures you control get +1/+1 until end of turn.

When Seishin Tidekeeper enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have flying.

Equipped creature gets +1/+0 for each colorless creature you control.
Equip {1}

Destroy target land. Add {R}{R}.

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Another target player reveals their hand. You may choose an instant or sorcery card from it and cast it without paying its mana cost.
Fuse (You may cast one or both halves of this card from your hand.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Sejiri Skyhunter, it gains flying until end of turn.

Whenever you cast a noncreature spell, put a number of charge counters on Selection at Danaj equal to that spell's mana value.
At the beginning of your end step, you may remove four charge counters from Selection at Danaj. If you do, look at the top four cards of your library, put one into your hand and the rest on the bottom of your library in a random order.

Create a 1/1 colorless Construct artifact creature token. If you control an artifact, create two of those tokens instead.

Enchant creature
Enchanted creature gets +1/+1 and has lifelink.

Menace
When Selfserving Ghul enters, remove two counters from target permanent.

{3}: Sellsword Contraption becomes the creature type of your choice until end of turn.

Senaturian Legion gets +1/+1 for each other creature on the battlefield named Senaturian Legion.
A deck can have any number of cards named Senaturian Legion.

Return target non-Horror creature to its owner's hand. Scry 1.

Return up to one target creature you control and up to one target creature you don't control to their owners' hands.

When Sending Stones enters, harmonize twice. (To harmonize, trigger up to one harmony of a permanent you control.)
If you would harmonize, you may trigger a harmony of a permanent card in your graveyard instead.